Nasal cavity and brain metastases from esophageal carcinoma detected by ⁶⁸ Ga-FAPI PET/CT

A 57-year-old male with a history of post-treatment esophageal squamous-cell carcinoma (ESCC) complained of a progressive headache. Suspecting tumor metastasis, this patient underwent ¹⁸ F-fluorodeoxyglucose ( ¹⁸ F-FDG) and ⁶⁸ Ga-fibroblast activation protein inhibitor ( ⁶⁸ Ga-FAPI) PET/CT scans as part of an investigator-initiated trial (NCT04416165). An increase of ¹⁸ F-FDG and ⁶⁸ Ga-FAPI uptake was observed in the left nasal cavity, which was confirmed as metastatic ESCC by nasal endoscopy biopsy. Additionally, several scattered lesions with increased ⁶⁸ Ga-FAPI uptake were observed in the brain. These lesions were subsequently confirmed as brain metastases by contrast-enhanced MRI. In this case, ⁶⁸ Ga-FAPI PET/CT showed superiority over ¹⁸ F-FDG in detecting uncommon metastases from ESCC, especially for identifying brain metastases.